It is important for a product to be well presented on a store shelf. For many products this will involve the package for the product. This is particularly the case for products that must be within a container on the store shelf. This includes liquid, gel, viscous, and powder products. Since such products usually will not be clearly seen at the time of purchase the decision to purchase a product will depend on the product presentation. This includes the container design, coloration, and the container graphics. The present invention is directed to the design and the coloration of the container. Many of the containers used today are thermoplastic containers, such as polyester containers that are blow molded from preforms. The preform can be clear or it can have a color. It is in the shape of an elongated tube and usually will have threads on an upper open end. The upper end will be essentially the same on the container as on the preform. In blow molding to a container the preform is heated to soften the thermoplastic so that it can flow during the stretch and blowing operations. The preform is stretch blow molded in a mold where the mold cavity has the negative of the exterior shape of the container that is being stretch blow molded. A rod stretches the preform longitudinally while the preform is being blown primarily laterally with a high pressure gas. The blow molded container will have the color of the preform and the shape of the mold cavity.
In the usual ways of making a thermoplastic based container, such as a polyester based container, the container can be clear or have a particular color. It will be clear or be the single color of the preform. The full preform, including the threaded neck will be of the same color. The problem then is how to efficiently improve the aesthetic appearance of containers. Using the processes of the present invention preforms and containers can be produced having an exterior color gradient, as well as a plurality of colors arrayed longitudinally around the container. These plurality of colors also can be in the form of color gradients. This is accomplished by an over molded thermoplastic layer over part or most of the preform and container. In addition, the containers can have varied colors through color differentiation and color matching. In color differentiation the preform can be of a first color and the over molded thermoplastic layer a different color with each being distinctly different colors. In color matching the preform will be of a first color and the over molded layer a complimentary color so that there can be perceived a third color by light passing through the two layers. Color matching will occur when the over mold layer has a thickness gradient over a wall of the container. This will be more apparent in a container blow molded from a preform where the over molded layer is of a decreasing thickness (gradient) allowing for the color of the container to be seen mixing with the color of the over molded layer and producing a tint of a third color. As an example a first color preform and a second color over molded layer will give each of these colors where the other color is visually absent and a varying blend in areas where there is a gradient in the thickness of the over-mold layer so that light is reflected from both colors. Thus a blue container will give a blue at one end where there is no over mold layer and green at the other end where solely an over-mold green layer is visually perceptive, with a blend of the two colors between each end. This will provide a great number of ways to decorate a container. The container can further be decorated by utilizing the color of the product within the container.
The prior art is directed to forming polyester preforms and coating these preforms with a coating of a barrier material. These will be moisture and/or gas barrier materials. The preforms then are blow molded by conventional processes and equipment to form the desired container. These usually are beverage containers. Such preforms and containers are disclosed in U.S. Pat. Nos. 6,391,408; 6,808,820 and 6,939,591. The objective in these patents is to produce containers with enhanced barrier properties. There is no disclosure as to how to significantly improve the aesthetic appearance of the containers as well as various physical properties. The over molding of polyester preforms and containers with elastomers is set out in my related application U.S. patent application Ser. No. 11/307,700, filed Feb. 17, 2007.